Background Layer Manager
The Background Layer manager lets you add, edit, and remove and manage the background layers that are associated with the model. The dialog box contains a list pane that displays each of the layers currently contained within the model, along with a number of button controls.
When a background layer is added, it appears in the Background Layers list pane, along with an associated check box that is used to control that layer’s visibility. Selecting the check box next to a layer causes that layer to become visible in the main drawing pane; clearing it causes it to become invisible. If the layers in the list pane are contained within one or more folders, clearing the check box next to a folder causes all of the layers within that folder to become invisible.
The toolbar consists of the following buttons: